Conclusion After launching Ubuntu on VirtualBox, I noticed that the network was not working. This turned out to be because VirtualBox requires manual switching between Wi-Fi and wired LAN.
Environment Ubuntu-20.04.4 VirtualBox 7.1.8 Steps Taken for Trouble Shooting 1. Check the current network status Type nmcli device status.
<network interface> ethernet connecting (getting IP configuration) netplan-<network interface> lo loopback connected (externally) It means the connection to wasn’t really connected.
2.Try to reconnect to network At first disconnect from current network: sudo nmcli device disconnect <network interface>
